Original article
Dental procedures in patients treated with antiplatelet or oral anticoagulation therapy – an anonymous survey Reingard Ringel and Renke Maas Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universit€at Erlangen-N€ urnberg, Erlangen, Germany
Gerodontology 2015; doi: 10.1111/ger.12181 Dental procedures in patients treated with antiplatelet or oral anticoagulation therapy – an anonymous survey Objective: To investigate how German dentists adhere to recommendations regarding dental treatment of patients taking antiplatelet or oral anticoagulation therapy for cardiovascular protection. Background: Discontinuation of antiplatelet or oral anticoagulation therapy prior to dental procedures is usually not recommended because the risk of thromboembolic events is higher than that of significant procedure-related bleeding. Materials and methods: An anonymous questionnaire regarding the handling of and experiences with patients taking aspirin (acetylsalicylic acid) or vitamin-K-antagonists (phenprocoumon) was distributed to approximately 4500 dentists attending the national German Dentists Day 2011. Results: Of 146 dentists who completed the questionnaire 77.4% and 27.6% stated that they perform tooth extractions under continued therapy with aspirin or vitamin-K-antagonists, respectively. When asked regarding the INR or Quick values, they require for tooth extractions in patients taking oral anticoagulants 29.5% of the dentists provided values that were outside the safe range (INR ≤1.5 or ≥3.5) and 90.7% accepted values too old to be clinically reliable. For pain relief after dental procedures, 71.2% of the dentists recommended ibuprofen notwithstanding the fact that it attenuates protective effects of aspirin and 10.2% would discontinue aspirin and prescribe ibuprofen or paracetamol (acetaminophen). Conclusion: Despite similar recommendations the majority of dentists perform tooth extractions in patients taking aspirin but not in patients taking vitamin-K-antagonists. Moreover, a potentially unfavourable drug interaction of aspirin and ibuprofen is frequently not considered. In patients taking vitamin-K-antagonists too many dentists rely on laboratory values that are too old or outside the recommended range. Keywords: oral anticoagulation, bleeding, aspirin, tooth extraction. Accepted 13 December 2014
Introduction An ageing society and a continuous expansion of the eligibility criteria for primary or secondary pharmacological prevention of cardiovascular and cerebrovascular events have led to an ongoing rise in the number of patients taking antiplatelet therapy (aspirin) or oral anticoagulation therapy with vitamin-K-antagonists such as warfarin or phenprocoumon. When these patients present for dental procedures, a potentially increased bleeding risk under continued antiplatelet or anticoagulation therapy has to be balanced against the risk of thromboembolic events in case the protective drugs
are discontinued prior to the procedure. Most current recommendations favour the performance of simple procedures such as tooth extraction under continued antiplatelet or anticoagulation therapy1. Data in the literature largely indicate that in patients taking aspirin the risk of thromboembolism outweighs the risk of bleeding2,3. As a consequence, it is usually not recommended to interrupt therapy with aspirin for tooth extractions4,5. Similar considerations apply to patients taking vitamin-K-antagonists6,7. Diverse specialist societies recommend the continuation of vitamin-K-antagonists in patients undergoing routine interventions such as simple tooth extractions1,8–11.
© 2015 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd
1
2
R. Ringel, R. Maas
Irrespective of these official recommendations in our regular clinical pharmacology counselling service as well as during continued medical education courses for cardiologists and dentists, we were repeatedly confronted with questions regarding the practical handling of patients taking aspirin or vitamin-K-antagonists. This indicated that physicians and dentists were either not aware of the official recommendations or had difficulties in adapting these to clinical practice. To investigate the type and extent of uncertainties regarding the handling of dental procedures in patients taking aspirin or vitamin-K-antagonists, we conducted this structured survey on the German Dentists Day.
Materials and methods Questionnaire A two-page questionnaire, titled ‘Dental procedures in patients taking aspirin or oral anticoagulants’, was developed (a copy of the questionnaire can be obtained from the corresponding author). It consisted of three sections: basic socio-demographic questions, a section regarding aspirin and a section regarding vitamin-K-antagonists. The socio-demographic section elicited information such as gender, professional category (dentist, oral surgeon, orthodontist, maxillofacial surgeon and others) and years of professional experience. For matters of comparability, only answers by respondents identifying themselves as ‘dentist’ were included into the present analysis. The first question of both subsequent sections was intended to identify the proportion of patients taking antiplatelet or anticoagulation therapy. The respondents were further asked to identify treatments they usually perform without discontinuation of aspirin or phenprocoumon (the most commonly used vitamin-K-antagonist in Germany). It was also asked who generally makes the decision regarding continuation or discontinuation of aspirin or phenprocoumon before tooth extractions. The next questions were intended to identify the percentage of patients taking aspirin/phenprocoumon for secondary prevention, in whom the respondents performed tooth extraction only after discontinuation and whether the dentist already had consulted with a patient who was bleeding, leading to hospitalisation. Drug interactions may have similar effects as direct discontinuation of the protective drugs. We
therefore included a question regarding the combined use of aspirin and ibuprofen, which may attenuate the protective effect of aspirin12. To assess whether this interaction is considered, it was asked which medication(s) is/are acceptable for pain relief in a patient who takes 100 mg aspirin per day after a myocardial infarction (possible answers: additional aspirin 500 mg, additional ibuprofen 400 mg, ibuprofen 400 mg instead of the aspirin, additional paracetamol (acetaminophen) 500 mg, paracetamol 500 mg instead of the aspirin, none of these therapy proposals I prefer). In the anticoagulant section, the dentists had to identify the range of laboratory values they consider acceptable for tooth extractions. The choice between an INR value of 1.5–4.0 and Quick value of 80–15% was given. This was followed by a question regarding laboratory values they require for therapeutic decisions and their timeliness (Quick method/INR value not relevant for therapy decisions, value not older than five days, value not older than 48 h, values not older than 24 h, values not older than 12 h and values not older than 6 h). At the end of the questionnaire, the dentists were invited to provide free text questions and recommendations they have regarding drug therapy in dental patients. Sample Together with the conference programme and an introductory cover letter, the questionnaire was provided to all (approximately 4500) participants of the national German Dentists Day (‘Deutscher Zahn€arztetag’) in November 2011 in Frankfurt/ Main. In the opening session of the conference, all dentists were encouraged to participate. Dentists attending the German Dentists Day came from all parts of Germany. Visitors had the possibility to drop their filled in questionnaire in a box on the German Dentists Day or also could send it via e-mail or fax till May 2012. Statistical analysis All data were analysed using the statistical software IBM SPSS statistics 20 (IBM Deutschland GmbH, Ehningen, Germany). Frequencies of discrete categories were compared using the chisquare test. An a-error probability of p < 0.05 was defined as the statistically significant level. Given the explorative nature, no further adjustments for multiple testing were made.
© 2015 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd
Anticoagulation and dental procedures - a survey
3
Of the approximately 4500 eligible dentists, 146 (3.2%) participated. The participants had on average 19.4 10.3 years of work experience, and 65.1% were male (one participant did not disclose his/her gender).
When asked about their preferred analgesic therapy in patients taking aspirin 100 mg for cardiovascular protection 105 (71.2%), dentists recommended ibuprofen 400 mg in addition to aspirin while 15 (10.2%) would prescribe ibuprofen 400 mg or paracetamol 500 mg and discontinue aspirin.
Dental procedures under antiplatelet therapy with aspirin
Dental procedures under oral anticoagulation with vitamin-K-antagonists
The dentists reported that a median of 10% (25– 75% percentile: 8–20%) of their patients are taking aspirin in the typical dose used for cardiovascular protection (100 mg) at the time of presentation. Asked regarding the type of procedures they generally perform in these patients, 96.6% reported that they usually infiltrate with local anaesthetics, 97.3% do scaling, 77.4% perform tooth extractions, and 28.1% insert implants, while 2.7% of the dentists indicated that they do not perform any procedures where a patient has taken 100 mg of aspirin. Conversely, 59.4% of the dentists reported that they at least occasionally perform tooth extractions only after discontinuation of aspirin 100 mg. Male dentists were more likely than female dentists to perform dental procedures in patients taking aspirin (83% vs. 66%, p = 0.023). However, the decision to continue or discontinue aspirin 100 mg prior to dental procedures is predominantly taken in consultation with the patients GP or specialist (Table 1). Eleven (7.5%) dentists reported that they had experienced at least one bleeding complication requiring hospitalisation of the patient. Of these, only three (27.3%) still generally perform tooth extractions in patients taking aspirin 100 mg, in contrast to 110 (81.5%) of the dentists who did not experience a bleeding requiring hospitalisation (p < 0.001).
In patients taking vitamin-K-antagonists 85.5% of the respondents infiltrate with local anaesthetics, 80.7% do scaling, 27.6% extract teeth, and 6.9% routinely do implant insertion without discontinuation of oral anticoagulation, while 11.7% do not perform any procedures in these patients. Male dentists were more likely than female dentists to perform dental procedures in patients vitamin-K-antagonists (36% vs. 12%, p = 0.002). The decision to continue or discontinue oral anticoagulation prior to dental procedures is predominantly taken in consultation with the patient’s GP or specialist (Table 1). Twenty-five (17.1%) dentists reported that they had experienced at least one bleeding complication requiring hospitalisation when performing a dental procedure in patients taking vitamin-Kantagonists. Of these, 24.0% still generally perform tooth extractions in patients taking oral anticoagulants, in comparison with 28.6% of the dentists who did not experience a bleeding patient requiring hospitalisation (p = 0.643).
Results
Table 1 Who usually takes the decision about continuation or discontinuation of antiplatelet or anticoagulation therapy before tooth extractions?
Dentist him/herself GP or specialist Dentist together with GP or specialist Patient a
Not answered: 7 Not answered: 3
b
Aspirin 100a
Oral anticoagulationb
37 (25.3%) 18 (12.3%) 83 (56.8%)
4 (2.7%) 52 (35.6%) 86 (58.9%)
1 (0.7%)
1 (0.7%)
Consideration of laboratory values to guide procedures in patients taking a vitamin-K-antagonist Before starting a dental procedure in a patient taking oral anticoagulants, only 22.9% require recent (≤12 h) INR or Quick values, and only 9.3% require values from the same day (i.e. not older than 6 h). When asked regarding the range INR or Quick they require for procedures (i.e. consider safe), 29.5% of the respondents who perform tooth extractions under continued oral anticoagulation provided values that were outside the safe range [i.e. too low (INR ≤ 1.5) with regard to the protection from thromboembolism or too high (INR ≥ 3.5) with regard to the bleeding risk] or mutually contradictive (six dentists did not answer this question). At the end of the questionnaire, the dentists were invited to provide free text questions and comments regarding general issues in drug therapy. In addition to the uncertainties regarding the appropriate handling of patients using the
© 2015 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd
4
R. Ringel, R. Maas
aforementioned drugs, several dentists also sought recommendations regarding procedures in patients taking newly introduced oral anticoagulants such as dabigatran and rivaroxaban.
Discussion The key observations of this anonymous survey among German dentists are as follows: 1. Prior to dental procedures such as simple tooth extractions antiplatelet therapy and especially oral anticoagulants are still more frequently discontinued than clinically recommended. 2. The decision to discontinue the protective medication is mostly taken in consultation with the general practitioner or specialist of the patients. 3. As compared to female dentists, male dentists are more likely to perform dental procedures in patients currently taking antiplatelet therapy or oral anticoagulation. 4. Many dentists rely on invalid or outdated INR or Quick values for therapeutic decisions. 5. When prescribing ibuprofen for pain relief in patients with cardiovascular disease, dentists frequently do not consider a common and potentially critical drug–drug interaction with aspirin. Dental procedures and unnecessary discontinuation of antiplatelet or oral anticoagulation therapy Already in 2001, the DGZMK (German Society for Dental, Oral and Orthodontic Medicine) issued a scientific statement that anticoagulation therapy should not be discontinued for routine dental procedures because the risk of a critical bleeding is likely to be lower than the risk of thromboembolism9. Similar statements were issued, among others, by British and American associations, indicating a ‘lack of a scientific basis for routine discontinuation of oral anticoagulation therapy before dental treatment’8 and stating that ‘there is little or no indication to interrupt antiplatelet drugs for dental procedures’13. However, despite these rather similar recommendations for aspirin and vitamin-K-antagonists, a majority of dentists perform tooth extractions in patients taking aspirin, but not in patients taking vitamin-K-antagonists. Our data indicate, however, that the unnecessary discontinuation of aspirin or vitamin-K-antagonists may actually be an issue involving the general practitioners and specialists of the patients. In a majority of the cases, antiplatelet therapy or oral anticoagulation may actually not be discontinued by the dentists on their own accord but
rather after consultation with the patient’s GP or specialist. This is alarming as well, as similar recommendations regarding anticoagulation therapy and smaller surgical procedures such as dental procedures have been repeatedly published in the German and English literature11,14,15. It can only be speculated that the GPs and specialists (i.e. internists, cardiologists and neurologists) are uncertain regarding the bleeding risks associated with dental procedures and thus overcautious regarding the use of aspirin and anticoagulants, while the dentists may not be well informed regarding patients’ risk of thromboembolism. Both may result in a (too) frequent decision for discontinuation of these drugs. A joint statement by dentists, surgeons and cardiologists is likely a step in the right direction13, especially if endorsed or adapted by other national societies. Reliance on invalid cut-off values and outdated laboratory results in patients taking vitamin-Kantagonists In patients on stable anticoagulation therapy with phenprocoumon or warfarin, the INR is frequently not determined on a daily basis. However, recent (same day or
Dental procedures in patients treated with antiplatelet or oral anticoagulation therapy – an anonymous survey Reingard Ringel and Renke Maas Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universit€at Erlangen-N€ urnberg, Erlangen, Germany
Gerodontology 2015; doi: 10.1111/ger.12181 Dental procedures in patients treated with antiplatelet or oral anticoagulation therapy – an anonymous survey Objective: To investigate how German dentists adhere to recommendations regarding dental treatment of patients taking antiplatelet or oral anticoagulation therapy for cardiovascular protection. Background: Discontinuation of antiplatelet or oral anticoagulation therapy prior to dental procedures is usually not recommended because the risk of thromboembolic events is higher than that of significant procedure-related bleeding. Materials and methods: An anonymous questionnaire regarding the handling of and experiences with patients taking aspirin (acetylsalicylic acid) or vitamin-K-antagonists (phenprocoumon) was distributed to approximately 4500 dentists attending the national German Dentists Day 2011. Results: Of 146 dentists who completed the questionnaire 77.4% and 27.6% stated that they perform tooth extractions under continued therapy with aspirin or vitamin-K-antagonists, respectively. When asked regarding the INR or Quick values, they require for tooth extractions in patients taking oral anticoagulants 29.5% of the dentists provided values that were outside the safe range (INR ≤1.5 or ≥3.5) and 90.7% accepted values too old to be clinically reliable. For pain relief after dental procedures, 71.2% of the dentists recommended ibuprofen notwithstanding the fact that it attenuates protective effects of aspirin and 10.2% would discontinue aspirin and prescribe ibuprofen or paracetamol (acetaminophen). Conclusion: Despite similar recommendations the majority of dentists perform tooth extractions in patients taking aspirin but not in patients taking vitamin-K-antagonists. Moreover, a potentially unfavourable drug interaction of aspirin and ibuprofen is frequently not considered. In patients taking vitamin-K-antagonists too many dentists rely on laboratory values that are too old or outside the recommended range. Keywords: oral anticoagulation, bleeding, aspirin, tooth extraction. Accepted 13 December 2014
Introduction An ageing society and a continuous expansion of the eligibility criteria for primary or secondary pharmacological prevention of cardiovascular and cerebrovascular events have led to an ongoing rise in the number of patients taking antiplatelet therapy (aspirin) or oral anticoagulation therapy with vitamin-K-antagonists such as warfarin or phenprocoumon. When these patients present for dental procedures, a potentially increased bleeding risk under continued antiplatelet or anticoagulation therapy has to be balanced against the risk of thromboembolic events in case the protective drugs
are discontinued prior to the procedure. Most current recommendations favour the performance of simple procedures such as tooth extraction under continued antiplatelet or anticoagulation therapy1. Data in the literature largely indicate that in patients taking aspirin the risk of thromboembolism outweighs the risk of bleeding2,3. As a consequence, it is usually not recommended to interrupt therapy with aspirin for tooth extractions4,5. Similar considerations apply to patients taking vitamin-K-antagonists6,7. Diverse specialist societies recommend the continuation of vitamin-K-antagonists in patients undergoing routine interventions such as simple tooth extractions1,8–11.
© 2015 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd
1
2
R. Ringel, R. Maas
Irrespective of these official recommendations in our regular clinical pharmacology counselling service as well as during continued medical education courses for cardiologists and dentists, we were repeatedly confronted with questions regarding the practical handling of patients taking aspirin or vitamin-K-antagonists. This indicated that physicians and dentists were either not aware of the official recommendations or had difficulties in adapting these to clinical practice. To investigate the type and extent of uncertainties regarding the handling of dental procedures in patients taking aspirin or vitamin-K-antagonists, we conducted this structured survey on the German Dentists Day.
Materials and methods Questionnaire A two-page questionnaire, titled ‘Dental procedures in patients taking aspirin or oral anticoagulants’, was developed (a copy of the questionnaire can be obtained from the corresponding author). It consisted of three sections: basic socio-demographic questions, a section regarding aspirin and a section regarding vitamin-K-antagonists. The socio-demographic section elicited information such as gender, professional category (dentist, oral surgeon, orthodontist, maxillofacial surgeon and others) and years of professional experience. For matters of comparability, only answers by respondents identifying themselves as ‘dentist’ were included into the present analysis. The first question of both subsequent sections was intended to identify the proportion of patients taking antiplatelet or anticoagulation therapy. The respondents were further asked to identify treatments they usually perform without discontinuation of aspirin or phenprocoumon (the most commonly used vitamin-K-antagonist in Germany). It was also asked who generally makes the decision regarding continuation or discontinuation of aspirin or phenprocoumon before tooth extractions. The next questions were intended to identify the percentage of patients taking aspirin/phenprocoumon for secondary prevention, in whom the respondents performed tooth extraction only after discontinuation and whether the dentist already had consulted with a patient who was bleeding, leading to hospitalisation. Drug interactions may have similar effects as direct discontinuation of the protective drugs. We
therefore included a question regarding the combined use of aspirin and ibuprofen, which may attenuate the protective effect of aspirin12. To assess whether this interaction is considered, it was asked which medication(s) is/are acceptable for pain relief in a patient who takes 100 mg aspirin per day after a myocardial infarction (possible answers: additional aspirin 500 mg, additional ibuprofen 400 mg, ibuprofen 400 mg instead of the aspirin, additional paracetamol (acetaminophen) 500 mg, paracetamol 500 mg instead of the aspirin, none of these therapy proposals I prefer). In the anticoagulant section, the dentists had to identify the range of laboratory values they consider acceptable for tooth extractions. The choice between an INR value of 1.5–4.0 and Quick value of 80–15% was given. This was followed by a question regarding laboratory values they require for therapeutic decisions and their timeliness (Quick method/INR value not relevant for therapy decisions, value not older than five days, value not older than 48 h, values not older than 24 h, values not older than 12 h and values not older than 6 h). At the end of the questionnaire, the dentists were invited to provide free text questions and recommendations they have regarding drug therapy in dental patients. Sample Together with the conference programme and an introductory cover letter, the questionnaire was provided to all (approximately 4500) participants of the national German Dentists Day (‘Deutscher Zahn€arztetag’) in November 2011 in Frankfurt/ Main. In the opening session of the conference, all dentists were encouraged to participate. Dentists attending the German Dentists Day came from all parts of Germany. Visitors had the possibility to drop their filled in questionnaire in a box on the German Dentists Day or also could send it via e-mail or fax till May 2012. Statistical analysis All data were analysed using the statistical software IBM SPSS statistics 20 (IBM Deutschland GmbH, Ehningen, Germany). Frequencies of discrete categories were compared using the chisquare test. An a-error probability of p < 0.05 was defined as the statistically significant level. Given the explorative nature, no further adjustments for multiple testing were made.
© 2015 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd
Anticoagulation and dental procedures - a survey
3
Of the approximately 4500 eligible dentists, 146 (3.2%) participated. The participants had on average 19.4 10.3 years of work experience, and 65.1% were male (one participant did not disclose his/her gender).
When asked about their preferred analgesic therapy in patients taking aspirin 100 mg for cardiovascular protection 105 (71.2%), dentists recommended ibuprofen 400 mg in addition to aspirin while 15 (10.2%) would prescribe ibuprofen 400 mg or paracetamol 500 mg and discontinue aspirin.
Dental procedures under antiplatelet therapy with aspirin
Dental procedures under oral anticoagulation with vitamin-K-antagonists
The dentists reported that a median of 10% (25– 75% percentile: 8–20%) of their patients are taking aspirin in the typical dose used for cardiovascular protection (100 mg) at the time of presentation. Asked regarding the type of procedures they generally perform in these patients, 96.6% reported that they usually infiltrate with local anaesthetics, 97.3% do scaling, 77.4% perform tooth extractions, and 28.1% insert implants, while 2.7% of the dentists indicated that they do not perform any procedures where a patient has taken 100 mg of aspirin. Conversely, 59.4% of the dentists reported that they at least occasionally perform tooth extractions only after discontinuation of aspirin 100 mg. Male dentists were more likely than female dentists to perform dental procedures in patients taking aspirin (83% vs. 66%, p = 0.023). However, the decision to continue or discontinue aspirin 100 mg prior to dental procedures is predominantly taken in consultation with the patients GP or specialist (Table 1). Eleven (7.5%) dentists reported that they had experienced at least one bleeding complication requiring hospitalisation of the patient. Of these, only three (27.3%) still generally perform tooth extractions in patients taking aspirin 100 mg, in contrast to 110 (81.5%) of the dentists who did not experience a bleeding requiring hospitalisation (p < 0.001).
In patients taking vitamin-K-antagonists 85.5% of the respondents infiltrate with local anaesthetics, 80.7% do scaling, 27.6% extract teeth, and 6.9% routinely do implant insertion without discontinuation of oral anticoagulation, while 11.7% do not perform any procedures in these patients. Male dentists were more likely than female dentists to perform dental procedures in patients vitamin-K-antagonists (36% vs. 12%, p = 0.002). The decision to continue or discontinue oral anticoagulation prior to dental procedures is predominantly taken in consultation with the patient’s GP or specialist (Table 1). Twenty-five (17.1%) dentists reported that they had experienced at least one bleeding complication requiring hospitalisation when performing a dental procedure in patients taking vitamin-Kantagonists. Of these, 24.0% still generally perform tooth extractions in patients taking oral anticoagulants, in comparison with 28.6% of the dentists who did not experience a bleeding patient requiring hospitalisation (p = 0.643).
Results
Table 1 Who usually takes the decision about continuation or discontinuation of antiplatelet or anticoagulation therapy before tooth extractions?
Dentist him/herself GP or specialist Dentist together with GP or specialist Patient a
Not answered: 7 Not answered: 3
b
Aspirin 100a
Oral anticoagulationb
37 (25.3%) 18 (12.3%) 83 (56.8%)
4 (2.7%) 52 (35.6%) 86 (58.9%)
1 (0.7%)
1 (0.7%)
Consideration of laboratory values to guide procedures in patients taking a vitamin-K-antagonist Before starting a dental procedure in a patient taking oral anticoagulants, only 22.9% require recent (≤12 h) INR or Quick values, and only 9.3% require values from the same day (i.e. not older than 6 h). When asked regarding the range INR or Quick they require for procedures (i.e. consider safe), 29.5% of the respondents who perform tooth extractions under continued oral anticoagulation provided values that were outside the safe range [i.e. too low (INR ≤ 1.5) with regard to the protection from thromboembolism or too high (INR ≥ 3.5) with regard to the bleeding risk] or mutually contradictive (six dentists did not answer this question). At the end of the questionnaire, the dentists were invited to provide free text questions and comments regarding general issues in drug therapy. In addition to the uncertainties regarding the appropriate handling of patients using the
© 2015 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd
4
R. Ringel, R. Maas
aforementioned drugs, several dentists also sought recommendations regarding procedures in patients taking newly introduced oral anticoagulants such as dabigatran and rivaroxaban.
Discussion The key observations of this anonymous survey among German dentists are as follows: 1. Prior to dental procedures such as simple tooth extractions antiplatelet therapy and especially oral anticoagulants are still more frequently discontinued than clinically recommended. 2. The decision to discontinue the protective medication is mostly taken in consultation with the general practitioner or specialist of the patients. 3. As compared to female dentists, male dentists are more likely to perform dental procedures in patients currently taking antiplatelet therapy or oral anticoagulation. 4. Many dentists rely on invalid or outdated INR or Quick values for therapeutic decisions. 5. When prescribing ibuprofen for pain relief in patients with cardiovascular disease, dentists frequently do not consider a common and potentially critical drug–drug interaction with aspirin. Dental procedures and unnecessary discontinuation of antiplatelet or oral anticoagulation therapy Already in 2001, the DGZMK (German Society for Dental, Oral and Orthodontic Medicine) issued a scientific statement that anticoagulation therapy should not be discontinued for routine dental procedures because the risk of a critical bleeding is likely to be lower than the risk of thromboembolism9. Similar statements were issued, among others, by British and American associations, indicating a ‘lack of a scientific basis for routine discontinuation of oral anticoagulation therapy before dental treatment’8 and stating that ‘there is little or no indication to interrupt antiplatelet drugs for dental procedures’13. However, despite these rather similar recommendations for aspirin and vitamin-K-antagonists, a majority of dentists perform tooth extractions in patients taking aspirin, but not in patients taking vitamin-K-antagonists. Our data indicate, however, that the unnecessary discontinuation of aspirin or vitamin-K-antagonists may actually be an issue involving the general practitioners and specialists of the patients. In a majority of the cases, antiplatelet therapy or oral anticoagulation may actually not be discontinued by the dentists on their own accord but
rather after consultation with the patient’s GP or specialist. This is alarming as well, as similar recommendations regarding anticoagulation therapy and smaller surgical procedures such as dental procedures have been repeatedly published in the German and English literature11,14,15. It can only be speculated that the GPs and specialists (i.e. internists, cardiologists and neurologists) are uncertain regarding the bleeding risks associated with dental procedures and thus overcautious regarding the use of aspirin and anticoagulants, while the dentists may not be well informed regarding patients’ risk of thromboembolism. Both may result in a (too) frequent decision for discontinuation of these drugs. A joint statement by dentists, surgeons and cardiologists is likely a step in the right direction13, especially if endorsed or adapted by other national societies. Reliance on invalid cut-off values and outdated laboratory results in patients taking vitamin-Kantagonists In patients on stable anticoagulation therapy with phenprocoumon or warfarin, the INR is frequently not determined on a daily basis. However, recent (same day or
